U.S. patent number 5,486,066 [Application Number 08/244,103] was granted by the patent office on 1996-01-23 for paving stone set and process and device for the manufacture thereof.
This patent grant is currently assigned to SF-Kooperation GmbH Beton Konzepte. Invention is credited to Gerhard Hagenah.
United States Patent |
5,486,066 |
Hagenah |
January 23, 1996 |
Paving stone set and process and device for the manufacture
thereof
Abstract
Paving stone set and process and device for the manufacture
thereof. In the case of lawn-paving blocks formed from paving
stones (10) spaced at a considerable distance apart, these are
joined together, against relative displacements, by a holding grid
(11) embedded in the paving stones (10) and comprising
tension-resistant strands. The said holding grid allows the
transfer of traction forces and hence the reciprocal safeguarding
of the paving stones (10) within a paving stone set held together
by the holding grid (11). The manufacture of the paving stone sets
is effected in a concrete stone mold which is conventional in its
principle. A flask (19) disposed on a molding plate (28) and a
drawing sheet (29) is divided in the horizontal plane (33),
creating a top part-flask (34) and a bottom part-flask (35). The
holding grid (11) is clamped between the two part-flasks during
pouring of the concrete. Following the completion of a paving stone
set, the bottom part-flask (35) is withdrawn from the concrete
stone mold. Demolding can now be carried out in the usual
manner.
Inventors: |
Hagenah; Gerhard (Worpswede,
DE) |
Assignee: |
SF-Kooperation GmbH Beton
Konzepte (Bremen, DE)
|
Family
ID: |
6445437 |
Appl.
No.: |
08/244,103 |
Filed: |
May 19, 1994 |
PCT
Filed: |
November 20, 1992 |
PCT No.: |
PCT/EP92/02670 |
371
Date: |
May 19, 1994 |
102(e)
Date: |
May 19, 1994 |
PCT
Pub. No.: |
WO93/10310 |
PCT
Pub. Date: |
May 27, 1993 |
Foreign Application Priority Data
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|
|
|
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Nov 23, 1991 [DE] |
|
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41 38 564.0 |
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Current U.S.
Class: |
404/45;
264/260 |
Current CPC
Class: |
B28B
23/0012 (20130101); B28B 23/022 (20130101); E01C
9/004 (20130101); E01C 5/08 (20130101); E01C
2201/167 (20130101) |
Current International
Class: |
E01C
9/00 (20060101); B28B 23/02 (20060101); B28B
23/00 (20060101); E01C 5/06 (20060101); E01C
5/08 (20060101); E01C 011/16 () |
Field of
Search: |
;404/42,43,45
;425/111,121,126.1 ;264/260 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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4364 |
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Oct 1979 |
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EP |
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259735 |
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Apr 1990 |
|
EP |
|
7206680 |
|
Feb 1972 |
|
DE |
|
2147649 |
|
May 1972 |
|
DE |
|
2752545 |
|
Jun 1978 |
|
DE |
|
150772 |
|
Sep 1981 |
|
DE |
|
3200184 |
|
Jul 1983 |
|
DE |
|
3038843 |
|
Nov 1991 |
|
DE |
|
6803753 |
|
Sep 1969 |
|
NL |
|
Primary Examiner: Neuder; William P.
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak &
Seas
Claims
I claim:
1. A device for the manufacture of paving stone sets comprising
concrete paving stones which are spaced apart and are joined
together by a holding grid,
said device comprising a concrete mold having a flask defining die
cavities for respective concrete paving stones, which flask rests
on a molding plate, wherein
a) the flask is divided along a horizontal partition plane
extending at a distance from a lower limit of the die cavities and
running approximately parallel to the molding plate,
b) the flask comprises a top part-flask, fixed against horizontal
movement, and a bottom part-flask which is horizontally movable
relative to said top part-flask,
c) the bottom part-flask comprises only transverse mold walls
extending in the direction of a drawing motion of the bottom
part-flask, and
d) means for drawing off the bottom part-flask from the molding
plate, relative to the fixed top part-flask, in the horizontal
direction.
2. The device as claimed in claim 1, wherein the bottom part-flask
comprises a drawing sheet having said mold walls and extending in
the horizontal direction, and is movable by said drawing sheet
horizontally out of and into the concrete mold.
3. The device as claimed in claim 1 or 2, wherein the flask is
configured such that the holding grid can be clamped between the
bottom part-flask and the top part-flask, parts of the holding grid
being respectively clamped between adjacent ones of said mold walls
of the part-flasks.
4. The device as claimed in claim 3, wherein the holding grid can
be clamped on three sides thereof between the bottom part-flask and
the top part-flask.
5. The device according to claim 4, wherein the top part-flask
exhibits, on the side situated to the rear in the direction of
drawing a longitudinal spar, the height of which corresponds to
that of the flask.
6. The device according to claim 5, wherein the holding grid, which
consists of an elastic synthetic material, can be drawn from a roll
by the drawing sheet which is movable to and fro, the drawing sheet
exhibiting projection-like holding members.
7. The device according to claim 1, further comprising a plurality
of rams (31), one for each cavity, which define an upper limit of
the cavities.
8. The device according to claim 7, wherein said partition plane
(33) extends at a distance at approximately 1/4 to 1/3 of the total
height of the paving blocks from said lower limit of the die
cavities.
9. A process for the manufacture of paving stone sets which
comprise spaced apart concrete paving stones and are joined
together by a holding grid made up of longitudinal strands and
transverse strands, wherein
a) a bottom part-flask is disposed on a base,
b) the holding grid is then disposed on the bottom part-flask,
c) after this, a top part-flask is disposed on the bottom
part-flask or on the holding grid, the holding grid being clamped
between the top part-flask and the bottom part-flask,
d) the concrete is then filled into the flask, which is open at the
top, the holding grid being configured such that the fresh concrete
filled into concrete mold is able to pass through openings formed
by the longitudinal strands and transverse strands,
e) pressure rams are next lowered into the flask from above,
whereupon the concrete is compacted,
f) the bottom part-flask is then withdrawn horizontally relative to
the horizontally fixed top part-flask,
g) the top part-flask is next moved upwards, and
h) the pressure rams are then raised.
Description
The invention relates to a paving stone set for lawn paving, in
which the paving stone set comprises concrete paving stones which
are spaced apart, creating wide longitudinal gaps and transverse
gaps suitable for plant growth, and are joined together by holding
grids and secured against displacement. The invention further
relates to a process and a device for the manufacture of paving
stone sets.
Paving blocks, which allow plant growth within gaps between the
paving stones, are gaining increasingly in importance. In order to
ensure a load-bearing capacity of the so-called "lawn paving
blocks" in respect of stationary and--to a limited extent--rolling
traffic, the paving stones need to be secured against displacement.
For this purpose, spacers have hitherto been disposed in the gaps,
by means of which spacers the adjacent paving stones are mutually
supported. In the case of the lawn paving according to EP-A-259
735, the paving stones are mutually supported by spacers which,
after a certain time, perish in the ground.
The laying of paving blocks of this type is complex. Moreover, the
spacers have to be produced and kept handy as separate elements of
the paving block.
From EP-A-0 004 364, a laying unit made from concrete paving stones
is known, in which the paving stones are joined by means of a
network and by means of concrete webs. The concrete webs extend in
the region of longitudinal gaps and transverse gaps. The network is
disposed closely adjacent to the bottom side of the concrete paving
stones. The holding grid, both in the region of the concrete paving
stones and in the region of the concrete webs and longitudinal and
transverse gaps, is embedded in concrete.
U.S. Pat. No. 1,592,591shows a device for the manufacture of clay
bricks and solid bricks joined together by a wire grid. The
interconnected bricks serve as an outer lining for walls. The
bricks are spaced apart, so that transverse and longitudinal gaps
are formed. These are then filled in with mortar. The production
mold comprises a top part and a bottom part. The bottom part is
closed off on its bottom side by a base. Parallel to this base runs
a partition plane which divides the mold.
NL-A-6 803 753 shows an individual concrete stone, which is passed
through by a grid, a process and a device for the manufacture of
said concrete stone.
The object of the invention is to propose, for the design of a lawn
paving block and its production, measures which represent a
simplification compared to the previous solutions and which ensure
moreover, in a simple manner, the long-term securement of the
paving stones of the installed paving block.
In order to achieve this object, the paving stone set according to
the invention is characterized in that the concrete paving stones
are joined together exclusively by the holding grid, in that the
holding grid consists of tension-resistant and non-perishable
elastic material and lies continuously exposed in the region of the
longitudinal gaps and transverse gaps, and in that the holding
grid, exclusively in the region of the concrete paving stones, is
fully embedded in the latter, and in that the holding grid, at a
distance from a bottom side of the concrete paving stones, is
embedded in the latter, which distance corresponds to one-quarter
to one-third the total height of a concrete paving stone.
A paving stone set respectively comprises a group of simultaneously
produced paving stones, which, in their manufacture, are joined
together into a unit by a holding grid embedded in the concrete.
The holding grid comprises longitudinal strands and transverse
strands, which are capable of absorbing tensile loads. The paving
stones of the lawn paving are consequently secured, in terms of
their relative position to one another, by members which are
capable of bearing a tensile load. In the region of the
longitudinal gaps and transverse gaps, no further connecting or
supporting members for the paving stones are arranged.
The holding grid is configured such that plant growth in the
otherwise continuously exposed longitudinal gaps and transverse
gaps is not impaired. The distances between the longitudinal
strands and transverse strands are also chosen according to the
invention such that, in the production of the paving stones, the
fresh concrete is able to pass through openings or meshes in the
holding grid. The spacing between the strands measures, for this
purpose, 2 cm to 5 cm, preferably around 3 cm.
The holding grid preferably extends at a distance from a side of
the paving stones, which bottom distance corresponds to
approximately one-third of the height of said paving stones.
As a result of this arrangement of the holding grid, special
measures are necessary in the production of the paving stone sets.
Manufacture is intended to be effected industrially in a
conventional stone-molding machine. This is equipped with a
concrete mold, which is known in principle. Forming part of this is
a molding plate, on which the concrete stones are molded and remain
until fully hardened. Also forming part of the concrete mold is a
frame-like flask having die cavities which are open at top and
bottom and are limited by longitudinal walls and transverse walls.
Finally, pressure rams are provided, which enter into the die
cavities from above in order to compact the concrete. In addition,
the concrete mold usually contains a drawing sheet disposed between
the flask and the molding plate.
A thus configured concrete mold is equipped with a flask which is
divided in height, namely in a plane running at a distance from the
base (molding plate), and consequently comprises a top part-flask
and a bottom part-flask. The two part-flasks together form, in each
case, the die cavities. The holding grid is disposed between the
part-flasks and is clamped or fixed between them.
According to the invention, the bottom part-frame is specially
configured, namely in such a way that, following the production of
the concrete stones of a paving stone set, the bottom part-flask
can be withdrawn, in a certain direction, from the region of the
concrete mold. The bottom part-flask therefore exhibits transverse
walls running exclusively in the transverse direction or in the
direction of the drawing motion.
Further features of the invention relate to the manufacture of the
paving stone set and to the configuration of the concrete mold.
Details of the latter and of the paving stone set are explained in
greater detail below with reference to the drawings, in which:
FIG. 1 shows a paving stone set or a part thereof in plan view,
FIG. 2 shows a section through the paving stone set according to
FIG. 1 in the sectional plane II--II,
FIG. 3 shows a section through the paving stone set according to
FIG. 1 in the sectional plane III--III,
FIG. 4 shows a concrete mold for the manufacture of paving stone
sets according to FIG. 1 in top view.
FIG. 5 shows the concrete mold according to FIG. 4 in
cross-section, in part having the pressure ram raised,
FIG. 6 shows the concrete mold in longitudinal section, in a
representation corresponding to FIG. 5,
FIG. 7 shows a detail of the concrete mold in longitudinal section,
the scale having been heavily enlarged,
FIG. 8 shows the individual parts of the concrete mold in a
position in preparation for a production cycle, in side view.
The illustrative embodiments represented in the drawings relate, on
the one hand, to a paving stone set as a laying unit for lawn
paving. On the other hand, details of a device (concrete mold) for
the production of such types of paving stone inserts are shown. The
concrete mold can also be considered, however, for the production
of paving stone sets which are not necessarily used as part of a
lawn paving.
The paving stone set according to FIGS. 1 to 3 comprises (concrete)
paving stones 10 arranged in longitudinal and transverse rows,
having a square ground plan. The height of the paving stones 10
corresponds to the usual height of such paving stones corresponding
to the expected load.
The paving stones 10 forming part of a laying unit or paving stone
set are joined together by elastic members which are capable of
bearing a tensile load, namely by a continuous holding grid 11.
This comprises longitudinal strands 12 and transverse strands 13.
The longitudinal strands 12 and transverse strands 13 are joined
together in the region of nodes 14. The thus configured holding
grid 11 consists of a suitable synthetic material, e.g. polyester.
Molding grids 11 of this type can be continuously manufactured in
corresponding continuous-casting machines. The material is
weather-resistant and durable against tensile loads.
The holding grid 11 is embedded fully in the concrete of the paving
stones 10, namely at an adequate distance from a bottom side 15 of
the paving stones 10. In the illustrative embodiment shown, the
holding grid 11 is at a distance from the bottom side 15, which
distance corresponds to approximately one-third of the height of
the paving stone 10.
For the use of a thus configured paving stone set (FIG. 1) for lawn
paving blocks, the paving stones 10 are large distances apart,
which distances are fixed by the holding grid 11. Wide longitudinal
gaps 16 and equally wide transverse gaps 17 are thereby produced
between the paving stones 10, which are arranged in rows. The
longitudinal gaps 16 and transverse gaps 17 have a width of 4 cm to
5 cm. Within these longitudinal gaps 16 and transverse gaps 17, the
holding grid 11 lies completely exposed. No spacers or connecting
webs are provided. Due to the spacings between the longitudinal
strands 12 and between the transverse strands 13, openings 18 or
meshes of the holding grid 11 are produced which guarantee
unhindered plant growth in the region of the longitudinal gaps 16
and transverse gaps 17. The spacing between the longitudinal
strands 12 and between the transverse strands 13 here measures
around 3 cm.
The laying units or paving stone sets configured in the described
manner are produced in a conventional stone-molding machine by
means of concrete molds exhibiting certain modifications compared
to the conventional concrete molds.
A concrete mold usually comprises a flask 19. This comprises an
outer frame 20 having longitudinal spars 21, 22 and transverse
spars 23, 24. Running within this frame 20 are longitudinal walls
25 and transverse walls 26. These bound die cavities 27, in which
the paving stones 10 are molded.
The frame 20, which is open at top and bottom, stands on a base, a
molding plate 28. This can directly form the bottom extremity of
the concrete mold. The finished paving stones rest on the molding
plate 28 until fully set.
In the present illustrative embodiment, a drawing sheet 29 is
provided as the bottom extremity of the flask 19. The drawing sheet
29 is consequently located between the flask 19 and molding plate
28. In the demolding operation, the drawing sheet 29 is withdrawn
from the concrete mold, according to arrow 30, in the horizontal
direction, so that the paving stones 10 then lie directly on the
molding plate 28 and can be transported away with this once the
flask 19 has been removed.
Pressure rams 31 having die plates 32 corresponding to the shape
and size of the die cavities 27 enter into these from above.
In order to embed the holding grid 11 in the paving stones 10
during their manufacture, the flask 19, in the illustrative
embodiment shown, is divided along an (imaginary) horizontal
partition plane 33. A top part-flask 34 and a bottom part-flask 35
are thereby produced. Both together produce the whole flask 19.
In the region of the partition plane 33 there extends the holding
grid 11. This is brought into position prior to the filling of the
concrete. The fresh concrete, which have been filled into the open
die cavities 27 from above, passes through the openings 18 or
meshes in the holding grid 11, so that the flask 19 or each die
cavity 27 is filled to the top with concrete.
The holding grid 11 is clamped or fixed between the part-flasks 34
and 35. In the present illustrative embodiment, the holding grid 11
is clamped on three sides only between the part-flasks 34, 35,
namely in the region of the longitudinal spar 22 and transverse
spars 23, 24.
The bottom part-flask 35 is configured such that the paving stones
10 can be demolded essentially according to the conventional
principle. For this purpose, after the paving stones 10 in the
individual die cavities 27 have been formed-out, the bottom
part-flask 35 is initially removed. This is withdrawn from the
region of the concrete mold, in the horizontal direction, according
to arrow 30. In order to enable this, the bottom part-flask 35
comprises the bottom part of the longitudinal spar 22 of the
(divided) frame 20, which bottom part is situated to the fore in
the direction of draw according to arrow 30. The said frame is
adjoined by transverse walls 26 running in the direction of the
drawing motion or by bottom parts of these transverse walls 26. The
bottom part-flask 35 consequently has no longitudinal walls 25. In
this region, below the longitudinal walls 25 of the top part-flask
34, there are formed corresponding, elongated, strip-shaped
cavities 41. These are infiltrated, in the manufacture of the
paving stones 10, by some concrete, so that the finished paving
stones 10 of a paving stone set exhibit, in the region of the
longitudinal gaps 16, fins 36 adjacent to the bottom side 15. These
fins 36 can be eliminated by a finishing operation. Since they only
in substantially reduce the cross-section of the longitudinal gaps
16, they can also however remain on the paving stones 10.
Following the withdrawal of the bottom part-flask 35, demolding can
proceed in the usual manner. The pressure rams 31 remain in the
pressure setting according to FIG. 7. The top part-flask 34 is
moved upwards into a position according to FIG. 8. The pressure
rams 31 are then raised. The molding plate 28, with the paving
stones 10 and the holding grid 11 embedded therein, can now be
transported away.
In the present illustrative embodiment, the bottom part-flask 35 is
connected to the drawing sheet 29. The bottom parts of the
transverse walls 26 are disposed as elongated edgings on the
drawing sheet 29. To the said drawing sheet, there are fitted, on
the one side, thrust rods 37, which enable, by means of a suitable
actuating member (pressure-medium cylinder), a to-and-fro motion of
the drawing sheet 29. By use of the drawing sheet 29, the bottom
part-flask 35 is withdrawn from or introduced into the region of
the concrete mold.
In the present case, the holding grid 11, which corresponds
essentially to the size of a paving stone set, is drawn section by
section from a roll (not shown). After a corresponding section of
the holding grid 11 has been introduced into the concrete mold, the
necessary piece is cut off. In the present illustrative embodiment,
there is fitted to the top part-flask 34, namely to the
longitudinal spar 22 situated to the fore in the direction of draw,
a cutting edge 38, which realizes the separating cut as the
part-flask 34 is lowered. The cutting edge 38 can also be disposed
outside the region of the flask 19, at a distance therefrom, the
holding grid 11 being cut off as it juts over the longitudinal spar
22 of the bottom part-flask 35. To the cutting edge 38, there is
herein assigned a lower, fixed counter-blade, so that when the
flask 19 is closed, the holding grid 11 is cut through and the
longitudinal spars 22 of the top part-flask 34 and bottom
part-flask 35 lie directly adjacent to each other and are thus able
to clamp the holding grid 11.
In addition, the holding grid 11 is brought by the bottom
part-flask 35 or by the drawing sheet 29 into the position within
the flask 19. For this purpose, the front margin of the holding
grid 11, which is in each case exposed, is fixed to a free margin
of the drawing sheet 29 or of the bottom part-flask 35, e.g. to
hook-shaped holding members 39.
From the original setting (not shown) of the drawing sheet 29
outside the concrete mold, the holding grid 11, as it is unwound
from the roll, is transported into the concrete mold (FIG. 8).
After this, the top part-flask 34 is lowered. The concrete is then
filled into the die cavities 27, which are open at the top. The
pressure rams 31 are thereafter lowered. The concrete is then
compacted by a jarring table 40 on which the concrete mold
rests.
Following the molding of the paving stones 10, the drawing sheet 29
is first retracted, in the described manner, with the bottom
part-flask 35, then the top part-flask 34 moved upwards and the
pressure ram subsequently raised.
The top part-flask 34 is configured such that the transverse walls
26 do not rest on the corresponding transverse walls 26 of the
bottom part-flask 35. Rather, the top part-flask 34 is supported by
the longitudinal spar 21, situated to the rear in the direction of
draw, directly on the molding plate 28 or on the drawing sheet 29.
Furthermore, the transverse spars 23, 24 of the top part-flask 34
rest on the corresponding transverse spars 23, 24 of the bottom
part-flask 35. The longitudinal spar 22 of the top part-flask 34,
which longitudinal spar is situated to the fore in the direction of
draw, also rests on the longitudinal spar 22 of the bottom
part-flask 35.
The paving stone sets which are thus manufactured can be
mechanically laid in an advantageous manner. For this purpose, a
laying machine according to German Offenlegungsschrift 34 11 350
exhibits a head for gripping a respective paving stone set. The
head comprises two clamping jaws running in the transverse
direction, which press the paving stones 10 together during the
laying operation. In order to secure the gap spacings between the
paving stones 10 in the longitudinal direction, it is necessary for
the head to be provided with spacers, which engage in the
longitudinal gaps 16 and fix the paving stones 10, during laying,
at corresponding distances apart.
The described concrete mold is also suitable for the manufacture of
paving stone sets or laying units which are not intended for lawn
paving blocks, but which nevertheless exhibit a fully embedded
holding grid. The gaps are in this case smaller or narrower.
* * * * *